View s8337 s8338-series datasheet:

S-8337/8338 Series STEP-UP, 1.2 MHz HIGH-FREQUENCY, PWM CONTROL SWITCHING REGULATOR CONTROLLER www.sii-ic.com © Seiko Instruments Inc., 2003-2010 Rev.4.0_00 The S-8337/8338 Series is a CMOS step-up switching regulator which mainly consists of a reference voltage circuit, an oscillator, an error amplifier, a PWM controller, an under voltage lockout circuit (UVLO), and a timer latch short-circuit protection circuit. Because its minimum operating voltage is as low as 1.8 V, this switching regulator is ideal for the power supply of an LCD or for portable systems that operate on a low voltage. The internal oscillation frequency can be set up to 1.133 MHz, via the resistor connected to the ROSC pin. With the S-8337 Series, the maximum duty ratio of PWM control can be control